Nail changes and association of osteoarthritis in digital myxoid cyst.

BACKGROUND: Digital myxoid cyst is relatively common on the digits. Nail changes and osteoarthritis are usually associated with this pathogenesis.

OBJECTIVE: The objective was to clarify this relationship and its significance by analyzing the clinical, radiologic, and pathologic data.

METHODS AND MATERIALS: Fifty-one patients with digital myxoid cysts were diagnosed and analyzed during a 5-year period.

RESULTS: Thirty-eight (74.5%) of 51 patients showed radiologic evidence of primary interphalangeal joint osteoarthritis in the affected digits. Among the 39 cysts removed surgically and examined pathologically, 28 were myxomatous and 11 were ganglion. Different clinical manifestations of nail change, including longitudinal grooves (20 cases), concave canaliform dystrophy (9 cases), "washboard" transverse lines (5 cases), and longitudinal grooves with beaded ridges (1 case) were found.

CONCLUSION: Osteoarthritis of the adjacent terminal joint is an important factor involved in forming digital myxoid cysts. Of the two cyst types, ganglion cysts are related to osteoarthritis more often than myxomatous cysts. Nail changes, secondary to matrix damage, are reliable clinical signs of underlying cyst formation. Understanding the pathogenesis of the digital myxoid cyst in relation to osteoarthritis and nail deformity helps inform the care of these patients.